BoilerFaultCodesMalvern Combi Fault codes & diagnostics
0 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Combi Natural Gas 24-30 kW 1995 onwards Discontinued
GC Number 47-555-02
Download the Malvern Combi manual
PDF
Versions & GC numbers
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Which version do you have?
The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 47-555-02 | Combi NG | 1995–present |
Status & diagnostic codes 10 operating states & engineer diagnostics
Not faults — these are normal operating states. Tap to expand.
10 operating states & engineer diagnostics
Not faults — these are normal operating states. Tap to expand.
10 Diagnostic Your boiler is struggling to accurately read its own operating temperature due to a sensor measurement error. 20 Diagnostic Your boiler is struggling to accurately read its own internal water temperature because the sensor responsible for this measurement is sending an incorrect or impossible signal. 30 Diagnostic Your boiler is struggling to accurately measure the temperature of the water, which is causing it to shut down for safety reasons. 40 Diagnostic Your boiler is struggling to accurately measure its own temperature, causing it to shut down for safety reasons to prevent overheating. 50 Diagnostic Your boiler's temperature sensor is providing an incorrect reading, which is causing the system to shut down to prevent overheating. 60 Diagnostic Your boiler has detected an incorrect temperature reading from one of its sensors, causing it to shut down for safety. 70 Diagnostic Your boiler has detected an incorrect temperature reading from one of its internal sensors, which is preventing it from safely heating your water or radiators. 80 Diagnostic Your boiler has detected an incorrect electrical reading from a temperature sensor, causing it to shut down for safety reasons. 90 Diagnostic Your boiler is experiencing an electrical communication error between its internal sensors and the main computer, preventing it from operating safely. 931 Diagnostic Your boiler has detected an issue with its internal electrical sensors and has safely shut down to prevent further complications.